Catalytic processes for selective organic synthesis are described. Organolanthanides and group 3 organometallics will be utilized as catalysts in a wide range of processes for the construction of complex organic molecules from rather simple, readily available precursors. A family of organometallic complexes will be synthesized exhibiting significant reactivity, selectivity, and catalytic turnover in the processes outlined. This requires substantial "tuning" of the metal and the ligand. Processes to be developed are expected to exhibit a high degree of regioselectivity and diastereoselectivity. At the outset, the chemistry to be carried out will be focused on fundamental aspects of the new synthetic methods. However, ready access to compounds generated by these methods will provide more efficient and economical means to synthesize biologically active materials of interest to the pharmaceutical industry. For example, the reactions can be sequenced to provide a dramatic increase in molecular complexity from simple starting materials to the final products. Furthermore, the methods are environmentally sound in that they proceed in a manner where no byproducts are generated (i.e., they proceed with "atom economy"). Several diverse areas, all catalyzed by the same class of organometallics, have been targeted for study. These include: 1) Development of hydrosilylation, hydroboration, and hydrocupration reactions. 2) Cyclization reactions of polyolefins and dienynes involving sequential reactions wherein the cyclizations are terminated by silylation or boration. The synthesis of both carbocycles and nitrogen heterocycles will be explored. 3) The further development of hydroamination reactions. We will focus on hydroamination/cyclization sequences and applications to the synthesis of complex nitrogen heterocycles. 4) Carbometalation/cyclization reactions will be explored utilizing organochromium species. 5) Ligands and catalytic systems designed for asymmetric synthesis will be explored.